The Fond du Lac County Register in Probate Office has probate records for Fond du Lac County dating back to 1848 when Wisconsin became a State. These records may be accessed during regular business hours. A $4.00 Search Fee is required if a staff member does a record check. If you come in and search the card index, no fee is charged. Copies are available at $1.00 per page.
The Wisconsin State Historical Society also has records available.